What is the registry?

- The Registry is this great mysteryinside of every computer,but if you think about it for a minute,it really makes a lot of sense.If you go back a million years,or at least back to versions of Windows, like Windows 95,everything you did within Windowswas configured through some form of text file,usually with the extension INI.In fact, Linux users are like, well yeah,that's how everything works, Mike,and there's nothing wrong with usingall these different initialization filesto configure things,but Microsoft felt a long time agothat life would be a lot easierif instead of using a gazillion text filesthat were all over the place,if we had one common storage area.

That common storage area is the Registry.The Registry is not a text file,it's a database,and you have to have a special readerto be able to read, edit, or do anythingyou want to this particular database.But, the important thing to appreciatewith the Registry is thatpretty much everything that is Windows,is in the Registry somewhere.Registries can be massive filesdepending on how much stuff you have loaded in there,and pretty much, anytime you go to control panel,change a screensaver, add a piece of software,anything you do,one of the main things you're doingis updating the Registry.

So, we're messing with the Registry all the time.However, there are times where you're gonna haveto go in to the Registry manually.Now, the A Plus does not expect you to become an expertat Registry manipulation.It does expect you,that if there is a problemwhere the Registry has to be accessed manually,that you understand it well enough,so if somebody's telling you to put in some bizarre command,or something like that,that you can open the Registry,do it the right way, create a backup,and make it work.So, let's dive in to the Registry.

So, to get to the Registry,all we need to do is type in REGEDIT.That's the reg edit,and this is actually the Registry editor itself.Remember, the Registry is not a text file,it's just like you need Microsoft Wordto edit a word document,it's its own particular format,and you have to use the Registry editor.Now, there's a long shot,but there use to be another program called REGEDT32.You see how I've got it typed there?REGEDT32,and back in the old days,there was actually two different ways to run it.

So, you can either type in REGEDIT or REGEDT32,and either one of these will get you to the Registry editor.The big thing you need to keep in mindwith the Registry editoris that you've got these five root keys.Okay, HKEY_CLASSES_ROOT is basicallydefines everything that is your computer.Every type of file, every type of data structure.It's monstrous,and it's not a place we have to go to very often,but that's what it handles.HKEY_CURRENT_USER is all the informationabout the currently logged in user.

So, everything from my screensaverto what my background looks like.Anything that I might have setup,that's gonna be showing up here under HKEY_CURRENT_USER.HKEY_LOCAL_MACHINE is informationabout this particular computer.What software's installed.What hardware's installed.How the security is set up.Pretty much everything that is this computeris under HKEY_LOCAL_MACHINE.Now, HKEY_USERS is nothing more thana list of all the different accountsthat are currently on this computer.

They're kinda encoded,and one of these is actually meright up here in HKEY_CURRENT_USER.So, if I were to break one of these down,you can actually see it looks similarto what you're seeing in HKEY_CURRENT_USERbecause it just grabs one of these,and makes that HKEY_CURRENT_USER.The HKEY_CURRENT_CONFIG is nothing morethan the current setup of the system,and that's like any particular issues with software,or hardware to be set up at any given moment.Okay?Make sure you know these five root keys for the A Plus exam.

Now, the one thing we like to domore than anything else with the Registryis that we will make subtle changes.A lot of times, it's not changesthat we actually understand,but it's because someone tells us to.Now, here's a very famous one.I'm gonna march you through it.You go to HKEY_LOCAL_MACHINE,and then, you go to SOFTWARE.Then, you go to Microsoft.You go down to Windows.Then, you go to CurrentVersion.

Underneath here are two little settingsthat are really kinda famous.It's called Run,and RunOnce.Run is the standard placefor most auto starting programs to appear.So, if you ever wanna actually take something offline,you would actually go to this particular location,and you could delete it.Now, the other thing I wanna show you,and that's on the A Plus,is that sometimes you do have to edit the Registry.So, one really important thingwe always do before we edit the Registryis we make a backup.

So, right now, you'll seethat I've got this Run highlighted.So, what I'm gonna dois I'm gonna export just this piece.I'm just gonna call it fred.And, what I've doneis I've taken just this one piece of the Registry,and I've got a back up copy of it.So, if I wanna delete anything outta here,so like here, I just can arbitrary delete a couple of thingsand so, I've deleted two things that auto start.

Now, if I were to suddenly discoverthat oh, I kinda wanted those.If I wanted to bring them back,all I would need to dois I can right click,and then, I can click on merge.You see that?So, any time I make a backup,it will, by the way, all backups have the last name REG,and I can bring it all backjust by hitting merge.Ta-da.There they are.So, that's the big stuff to remember about a Registry.

CompTIA does not expect you to become a Registry genius.Nobody knows the entire Registry,but it does expect you to know how to access a registry,how to make modifications to Registry settings,how to export,and how to recover exports in case you need them.That's about it.(upbeat music)

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8/5/2016

The CompTIA A+ Exam Prep series is a comprehensive six-part series designed to help IT professionals prepare for the CompTIA 220-902 exam, which focuses on operating systems and software. If you're looking to pass the exam for the first time or studying for renewal, this is the series for you.

Part 3 covers the Windows operating system: all the basics you need to know to troubleshoot the inside of a PC. Author and CompTIA expert Mike Meyers takes a look under the hood at the processes, services, and tasks and provides an overview of user management, which is one of the foundations of Windows security. In Chapter 3, you'll learn some techniques for maintaining and optimizing the performances of Windows, including backup and restore procedures. Every lesson maps to a question in the critical Windows domain—an estimated 30% of the exam.